Later, in the sutta, Buddha explains, he didn’t say “yes” to Q1, because it would be inconsistent with his claim of arising of the knowledge that “all phenomena are non-self (sabbe dhammā anattā).”

And, if the Buddha said “yes” to Q2, the wanderer Vacchagotta, already confused, would have fallen into even greater confusion, thinking: “It seems that the self I formerly had does not exist now (ahuvā me nūna pubbe attā).”

It appears the Buddha thought the idea of the non-existence of a self is incomprehensible for the wanderer Vacchagotta.

It's clear that by the time of the Three Qin (三秦) period (352–431 CE) when the sutta was translated, the Chinese translator/s also understood the attā as self (我).

It appears the Buddha thought the idea of the non-existence of a self is incomprehensible for the wanderer Vacchagotta.

Good post. However, I think we should also consider that when the wanderer Vacchagotta used the words "atta" his understanding of the word may have also differed from the Buddha. In other words, I think we should avoid imputing any Buddhist definitions upon words spoke by Vacchagotta given Vacchagotta had no understanding of Buddhism and was merely asking questions from his own doctrinal base.

However, I think we should also consider that when the wanderer Vacchagotta used the words "atta" his understanding of the word may have also differed from the Buddha. In other words, I think we should avoid imputing any Buddhist definitions upon words spoke by Vacchagotta given Vacchagotta had no understanding of Buddhism and was merely asking questions from his own doctrinal base.

Having read the Wiki article mentioned in the OP, my money is on "Ātman" (an everlasting soul kind of thing). Isn't "an everlasting soul" is very common in Hinduism since ages?

In other words, I think we should avoid imputing any Buddhist definitions upon words spoke by Vacchagotta given Vacchagotta had no understanding of Buddhism and was merely asking questions from his own doctrinal base.

Yes, but the Buddha must have understood what Vacchagotta meant by "atta". Otherwise, he would have question back the Vacchagotta. Do you think Buddha would blabber just for the sake of his own satisfaction like some modern gurus without regarding the audience?

“Do not go by oral tradition, by lineage of teaching, by hearsay, by a canonical tradition, by logical reasoning, by inferential reasoning, by reasoned cogitation, by the acceptance of a view after pondering it, by the seeming competence of a speaker, or because you think: ‘The ascetic is our guru.’”
- Kālāma-sutta

“Any action performed with greed—born of greed, caused by greed, originating from greed: Wherever one’s selfhood [atta-bhāva] turns up, there that action will ripen. Where that action ripens, there one will experience its fruit, either in this very life that has arisen or further along in the sequence.

“Any action performed with non-greed—born of non-greed, caused by non-greed, originating from non-greed: When greed is gone, that action is thus abandoned, its root destroyed, made like a palmyra stump, deprived of the conditions of development, not destined for future arising.

in both cases there is a doer, someone who makes these actions while in one case atta-bhava rises. Looks like 'nutriment' and 'becoming' can be used to form another word.

A person unknowing:
the actions performed by him,
born of greed, born of aversion,
& born of delusion,
whether many or few,
are experienced right here:
No other ground is found.1

bad destinations cut.., so even if actions doesn't bear fruit there still will be good destinations(tho translator commentator note doesn't agree). I think Arhant(according to translator its Arhant) whos actions doesn't cause rebirth will still born or have that capability.

by reason someone without greed.. don't have atta-bhava because it won't 'turn up'(turn up? what's that exactly, any other suitable words?).
also it seem both variants doesn't have atta-bhava, it requires actions.

Seriously though, I can't see any practical difference between the view of "no-self" and the view of "everything is not-self".

The sutta appears quite clear about Vacchagotta's wrong view. Vacchagotta might have taken on blind faith he was not a self in the present but would have held he was a self in the past; which would not have been the view that "everything" is not-self.

Vacchagotta wrote:“It seems that the self I formerly had does not exist now (ahuvā me nūna pubbe attā).”

SN 22.79 appears to explain the right view; where past ignorant mistaken "self-making" or "birthing" is correctly viewed as not-self.

At Savatthi. “Bhikkhus, those ascetics and brahmins who recollect their manifold past abodes all recollect the five aggregates subject to clinging or a certain one among them. What five?

“When recollecting thus, bhikkhus: ‘I had such form in the past,’ it is just form that one recollects. When recollecting: ‘I had such a feeling in the past,’ it is just feeling that one recollects. When recollecting: ‘I had such a perception in the past,’ it is just perception that one recollects. When recollecting: ‘I had such volitional formations in the past,’ it is just volitional formations that one recollects. When recollecting: ‘I had such consciousness in the past,’ it is just consciousness that one recollects.

“Therefore, bhikkhus, any kind of form whatsoever … Any kind of feeling whatsoever … Any kind of perception whatsoever … Any kind of volitional formations whatsoever … Any kind of consciousness whatsoever, whether past, future, or present, internal or external, gross or subtle, inferior or superior, far or near, all consciousness should be seen as it really is with correct wisdom thus: ‘This is not mine, this I am not, this is not my self.’

“This is called, bhikkhus, a noble disciple who dismantles and does not build up; who abandons and does not cling; who scatters and does not amass; who extinguishes and does not kindle.

Seriously though, I can't see any practical difference between the view of "no-self" and the view of "everything is not-self".

The sutta appears quite clear about Vacchagotta's wrong view. Vacchagotta might have taken on blind faith he was not a self in the present but would have held he was a self in the past; which would not have been the view that "everything" is not-self.

Vacchagotta wrote:“It seems that the self I formerly had does not exist now (ahuvā me nūna pubbe attā).”

SN 22.79 appears to explain the right view; where past ignorant mistaken "self-making" or "birthing" is correctly viewed as not-self.

At Savatthi. “Bhikkhus, those ascetics and brahmins who recollect their manifold past abodes all recollect the five aggregates subject to clinging or a certain one among them. What five?

“When recollecting thus, bhikkhus: ‘I had such form in the past,’ it is just form that one recollects. When recollecting: ‘I had such a feeling in the past,’ it is just feeling that one recollects. When recollecting: ‘I had such a perception in the past,’ it is just perception that one recollects. When recollecting: ‘I had such volitional formations in the past,’ it is just volitional formations that one recollects. When recollecting: ‘I had such consciousness in the past,’ it is just consciousness that one recollects.

“Therefore, bhikkhus, any kind of form whatsoever … Any kind of feeling whatsoever … Any kind of perception whatsoever … Any kind of volitional formations whatsoever … Any kind of consciousness whatsoever, whether past, future, or present, internal or external, gross or subtle, inferior or superior, far or near, all consciousness should be seen as it really is with correct wisdom thus: ‘This is not mine, this I am not, this is not my self.’

“This is called, bhikkhus, a noble disciple who dismantles and does not build up; who abandons and does not cling; who scatters and does not amass; who extinguishes and does not kindle.

In summary, it appears in the view of enlightenment, there was never ever any self; that any "self" ideas in the past were mistaken.

Also, it seem that sense bases are not self; objects what we see are not self. While its actually clinging aggregates what are not self while they are considered as self(there is no discernment at first) in past, present and future, but the nibbana is not in a category of past, present, future near or far i think that's why they will be found(through path) to be not self.
-
Thats prolly why its when you see certain way you are called X, there is no further things to do.